In this passage, the character's actions that challenge cultural norms are illustrated through Molly taking over the cannon after her husband dies. The context reveals that during a time of battle, it was not typical for women to be directly involved in combat or to take on such roles as cannon operators. Molly's bravery and capability in a traditionally male-dominated space highlights her defiance against societal expectations of women during that era. Therefore, the correct answer is:
Molly takes over the cannon after her husband dies.